Bitcoin Forum

Testnet Pool: http://dot-bit.org/forum/viewtopic.php?p=1576#p1576

Wiki: http://dot-bit.org/MergedMining

Forum thread: http://dot-bit.org/forum/viewtopic.php?f=5&t=217&start=10#p1242

README by vinced: https://github.com/vinced/namecoin/blob/mergedmine/doc/README_merged-mining.md

Source: https://github.com/vinced/namecoin

Benefits
- Increased network security for both block chains (more hashing power, as you no longer need to choose between mining one or the other).
- Mining becomes more profitable (mining two currencies at the same hash rate for the same kWh. If you don't care about Namecoin you can just sell the mined NMC for BTC).

A list of reasons and benefits for this change would be appreciated, especially for the community that is going to be using it.

Sounds interesting, I'll look into it this weekend.
thx

- Increased network security for both block chains (more hashing power, as you no longer need to choose between mining one or the other).
- Mining becomes more profitable (mining two currencies at the same hash rate for the same kWh. If you don't care about Namecoin you can just sell the mined NMC for BTC).

Those are the ones I can think of.

So basically this will split mining with my hashrate between BTC and NMC equally? Is there any flexibility to this?

I can think of several scenarios where I would want to mine one more over the other in terms of percentage of my total hashrate. What details on the granularity of the settings for mining both exist?

Hasn't this functionality already existed in current miners?  I can simply fire up a miner or two or three using the same OpenCL device and point them to multiple pools.  So I could fire up 2 vs btcguild, one vs deepbit, one vs slush and one vs bitparking and have roughly 4:1 split on mining power between the two block chains with built-in redundancy for pool failure.

Am I missing something here?

edit: apparently I am.  very clever.  going to check into how I can implement this.

If you have a mining power of 100 mhash/s and just open 2 miners you would end up mining BTC and NMC at 50 mhash/s each. With the merged mining approach you would mine each at 100 mhash/s. Basically you are computing 1 hash and then submitting that hash to both block chains to see if it's under the target in either one.

How would you submit a hash to both NMC and BTC networks when they have different difficulties?

If you get a hash below the target of both chains then you announce you have solved a block in each one. If your hash is only below the target of one chain then you only announce to that one and nothing happens in the other.

If you meant how the low level stuff with merkle trees work then I have no idea.

Thank's a ton, having a hard time getting this to run on Windows 7 though.  Any help would be appreciated guys.  Peace!

Okay wait. So then that would mean the hashing would include namecoin transactions into the bitcoin block chain and vice versa. How is this going to work when they are two separate networks?

Am I missing something?

I do get the idea of finding a hash that fits Namecoin and Bitcoin or just Namecoin.

Since namecoins difficulty value is less than bitcoin, the only case would exist where it would benefit you is you could get a hash that is less than both namecoin's threshold and bitcoin's threshold but not the other way around unless namecoin's difficulty goes above bitcoin's or they some how become equal someday.

Still a little unclear...

Me too.  But maybe something like this:

• no change to miners, they just getwork and hash like normal...
• lots of changes to pools, new patched bitcoind and namecoind, etc...
• pool sends out getworks that are 'compatible' between both chains
• if a miner sends a proof-of-work that is of at least Namecoin difficulty, the pool gets a Namecoin block
• if a miner sends a proof-of-work that is of at least Bitcoin difficulty, the pool gets a Namecoin block and a Bitcoin block

(assuming that Namecoin difficulty is below Bitcoin difficulty.    Parity here we come....)

How odes that work mathematically?

As in: The GetWork woul dbe different, so the solutions too. I dont see this working at all, purely from a mathematical point of view.

Here is a wiki entry that does a better job at explaining things: http://dot-bit.org/MergedMining
Thanks to Nodemaster for putting it together.


Sorry I don't get how it works mathematically either, but just so you know it is already working on the testnets. The information of how it works at the low level is here: https://github.com/vinced/namecoin/blob/mergedmine/doc/README_merged-mining.md

This is very interesting. The first few pools to implement this should see a lot of hashing power flocking over to try it. The race is on?

Right. miners stay the same. Its completely transparent to them. they won't even recognize that they mine on two blockchains if you don't tell them.

Right. I have tested it on testnet with an uncomplete interface of my namecoin pool and start to build an alpha version of my pool in order to let interested people try it (on testnet) in order to make sure there are no unknown issues with some or specific miners. Alphaversion will be ready in the next week.

bitcoind need to be patched in order to have support for auxiliary (in our case namecoin) blockchain.

namecoind will undergo some major changes on block (proposed) 24000 in order to be able to act as auxiliary blockchain.

In fact there is a proxy (merged-mine-proxy) who connects to the bitcoind and namecoind. You can connect your miners to this proxy or let for example pushpoold connect to it.

Right. It is added to your namecoinds blockchain

No it'll get only a bitcoin block.

With a reasonable low probability it might however be possible that a solution fits both blockchains.


Not nessecarily. Merged mining is of course optional. Each pool operator can decide if he only mines bitcoin, namecoin or do merged mining. However i guess that most users might switch to merged pool as soon as they are available. Thus in a way there will be parity if merged mining is successful.


One thing that wasn't mentioned before (or I missed it) is that this is not only a bitcoin/namecoin thingy. It is possible to have several auxiliary blockchains (however ATM there are no others I know about). Thus if there are more bitcoinlike implementations they all might have a good start (or better start) as long as pool operators start to add them to their pools.

And forgot to add, that bitcoind not nessecarily need to be the parent blockchain. There is a patch available, that lets you use it as auxiliary blockchain and for example use namecoin as parent. But is easier to patch bitcoin with the "parent"-patch, as the difficult part with the change in blockchain will be done in namecoind at (proposed) block 24000 and can be found then in stock namecoind.

Sounds cool, and I'd definitely like to give it a try, but it won't be implemented until block 24000? I guess you guys need time to get it going, but that will be quite a while looking at historic trends. On 7/21 block 16128 the difficulty drops and people will rape namecoin for a few days, then drop out when difficulty erupts again (2-4 days later?), after which it will take 1-2 months to reach block 18144, etc. At that rate it will take half a year or more to reach 24k, is that intentional?

I'd be interested in seeing pools implement this in weeks, not months  >:(
The first pool to do this would have me switch over pretty quick.

Yeah, sort of. In fact we need more or less an entire namecoind update for all users at the same time. This is no easy going. All users need to be prepared. As blocks generated with the namecoind with merged mining patch will be rejected by older clients and vice versa. This is one reason why we use bitcoind as parent. using bitcoind as aux blockchain would nearly be impossible as there are way too many clients that would need to be updated. Using bitcoind as parent gives a smooth migration path for bitcoin users. But bear with the poor namecoin users who need time.


Yeah, me too  ;D On testnet it IS implemented for my pool, but unfortunately generated namecoins are rejected by the unpatched clients (reason see answer above). Thus it won't make any sense to start now. If everybody agrees on this it will be block 24k.

This sounds too good to be true.

Where's the disadvantages list?

Does this cause some kind of delay in processing blocks of child chains?

If for example my combined hashing power manages to snag me a block on the parent chain once a month or so on average, so that I am able to insert some kind of merkle or hash into the parent chain, how will my child chain proceed during the month or so until its miners succeed in inserting another block into the parent chain?

-MarkM-

For bitcoin users and miners in general it's a low hanging fruit BUT:

* For namecoin users this means a major change, as the blockains won't be compatible between the version below block 24k and above 24k.
* This all is completely untested. Okay, not completely. But it is in review and testing stage.
* A further daemon means more overhead for pool operators. However if merged mining gets common it might make sense to integrate it into pushpoold
* The pool operator has to administrate (at least) two blockchains.
* As long as the bitcoind parent patch is not in stock bitcoind pool operators have to patch bitcoind
* Pool operators who want to use merged mining need to adapt it to their pool frontend
* In theory a miner doesn't know if his pool does merged mining. Thus a pool operator could take all the coins from aux chain for himself. But I guess if you are not trusting your pool operator you are mining solo anyway.

What about the economic performance disadvantages of the respective currencies?

Won't this devalue bitcoin?

Good question! Please Discuss! (We had a similar discussion on dot-bit.org forum. But I feel we need much more opinions on this issue.)

There are many unanswered questions to these changes at block 24,000. These concerns need to be answered soon and get attention widely on the major discussion threads of the bitcoin forum.

I would hate to see this merged mining go south and people who had namecoins not be able to use their namecoins because of a possible screw up on the block chain with the merged mining development/implementation.

There are plenty of blockchains waiting in the wings, as soon as aux blockchain mining is worked out and debugged and understood there will probably be quite a few chains looking to be aux chains.

So please help them understand! :)

-MarkM-

You seem to be in the know ... care to share your wisdom?

I'm curious about the other blockchains hiding out there as well...

Definitely like the idea of doing it with namecoin, would help get it more mainstream I think.

I think this would devalue bitcoins, as well as any other coins that get added.  Hundreds of new coins will be added at no extra cost (as markm already confirmed).  All of those coins will be at jeopardy of losing value and might even get rejected.

This would be akin to everyone being able to print their own money and trying to get others to accept it.  With a few select currencies, it's easy for them to succeed.  With thousands to choose from, people aren't going to accept every type of payment someone thinks up.

As good as it might sound, especially for miners, this will probably lead to demise of many currencies, many of which probably didn't have a chance anyway but some that might have had a chance will die off as well.

Isn't the allure of BTC and other currencies like NMC the idea that an entity isn't able to print money whenever they feel like it?  This would be the same thing.  Miners would be mining mainly for BTC while in the process, printing extra money that will end up having a nearly constant exchange rate between BTC, NMC, etc, thus increasing the money supply and devaluing all of those currencies.  People are worried about the US having to print money to stay afloat because it could eventually lead to hyperinflation making the USD worthless.  All the coins following this path will also have that same risk.  People want to adopt BTC because they believe that can't happen with the currency.

For all of our sake, I hope everyone will reject this idea and it won't make it into any official branch, or even unofficial ones.

NMC does have a purpose though... unless other blockchains with a purpose were started, why would anyone mine them?

It's not just about purpose.  As a real world example, take the USD.  It serves a purpose and has been the reserve currency for over half a century.  If they start printing a lot more money, would you rather someone paid you in USD or a currency that doesn't need to go through major devaluation like AUD?

Also, not everyone believes in NMC.  Anyone can come up with blockchains with a "purpose" that a niche will enjoy mining in.  When mining in 100 currencies costs the same as mining in 1, people won't care that they're mining in a currency that's used to pay for videos of someone torturing insects.  If you're not for that cause, someone else will be and you not mining in a pool of only 20 currencies with ideas you believe in will cause you to earn much less than the people that are mining in all of them.

Remember once NMC and BTC are both mined at the same time, the exchange rate between the two will eventually be fairly constant.  It'd be like the BTC was considered as a USD $20 and an NMC a USD $1, effectively increasing the money supply of the base currency (BTC) and devaluing both.

Probably talking about Multicoin (http://forum.bitcoin.org/index.php?topic=24209.0), Groupcoin (http://forum.bitcoin.org/index.php?topic=24813.0), Goldcoin and Stablecoin (http://forum.bitcoin.org/index.php?topic=29135.0). Personally I don't see much value in Groupcoin, Goldcoin and Stablecoin. Can't comment in Multicoin because I don't get it.


The cost of mining BTC will stay equal. The only way that merged mining would be able to devalue BTC is if people start caring more about NMC (or any other currency) and they sell their BTC for it.


They wouldn't be able to do that because decrypting/cracking passwords requires a different type of computation, so if they added something like that to their software the hashing speed of miners would noticeably diminish.

I'd agree to the devaluation arguments if (and only then), when we could mine for new coins endlessley. But this is not the case. After for example all bitcoins have been mined merged mining assures, that there are still many people mining for perhaps another blockchain making sure the bitcoin blockchain is still strong.

Most people who shout "devaluation" seems to think the value for BTC emerges from the 50 coins generated for one block. If this is true, BTC will be doomed and useless as soon as the last bounty block is generated. Perhaps earlier ( when the bounty decreases first time)

To me, saying that merged mining will devalue bitcoins is akin to saying that printing more yens will devalue the dollar.

I never said it wouldn't stay equal.  However, by merging all these other ones into it, you effectively could get 100 different other ones at no cost to you.  Why would the average person only want to mine in one currency when they can do it in 100 different ones?  By not doing so, you're effectively getting only 70% (assuming BTC are worth 70% of the worth of all 100 currencies) compared to what other people are getting.  People wouldn't need to necessarily care about currency X as long as the currency still has a trade value for something with a more widespread purpose (BTC).

However, let's assume that people don't care about all these other currencies.  What's going to happen is there will be massive inflation in those currencies due to merged BTC mining and then people will start rejecting those currencies, causing them to fail.


No, this is akin to saying instead of just being able to print more yen, you'd be able to print JPY, USD, CAD, AUD, ZWD, etc at the same cost in resources.  People that have JPY, USD, CAD, or AUD will be in jeopardy of devaluation and eventually a failed currency.  People with ZWD won't care as much because it's basically worthless and failed already.  Because all these other currencies are being printed at the same time as JPY, people can effectively use the other currencies as substitutes for JPY, causing effectively an increase in the JPY money supply and driving its worth down along with all the other printed currencies.


This is effectively what can happen.  Instead of being limited by the 21m coins, you're creating these other pseudo-BTC.  With enough time and as long as they haven't failed, there will be a tightly knit relationship between those currencies.  Also, BTC won't reach its limit for another 100 years, and that's plenty of time for it to fail.

I'm not saying this will happen but I think it's a very likely scenario.  However, I'm fairly certain that what will come out of this will be a lot of failed currencies that might have had a chance to exist if they weren't merged.  I don't think there has ever been a time when you could print 100 different currencies by only printing 1 so there isn't anything directly related to compare against.  I see pseudo-BTC will come out of it (thus, leading to devaluation and a higher risk of failure) while you and JohnDoe don't.  What's certain though is that all currencies that inflate beyond sustainability end up in failure.  IMO, there is a lot more downside to merged mining than upside.

Can somebody please explain this sentence to me more thoroughly please? (From the wiki http://dot-bit.org/MergedMining#Goal_of_this_namecoin_change (http://dot-bit.org/MergedMining#Goal_of_this_namecoin_change))

For namecoin users this means a major change, as the blockains won't be compatible between the version below block 24k and above 24k.

So does that mean that any namecoin mined before block 24,000 will be invalid?

Or what exactly does that sentence mean?

Will I still be able to "spend", "use", "buy" and "sell" the namecoins I mined before block 24,000?

It only means that after block 24,000 people who haven't upgraded their clients won't be able to generate blocks because they'll be rejected by the majority (assuming the majority has updated). NMC mined before block 24,000 will be valid. Also block 24,000 is only a tentative date, it's not set in stone yet.

@jollyjim: Sorry, I just don't see any logic in your argumentation. Guess we'll have to wait and see what happens.

Merged mining is an implementation of the design outlined in this document I wrote some time ago:

https://en.bitcoin.it/wiki/Alternative_Chains

You can learn more about how it works there.

Whoaaa! Didn't know that. This document is awesome. This will help explaining it a lot. And I was reading source code to understand it  ::) This is so much better! BTW Thank you for making this possible.

If you are brave and want to test merged mining on the most alpha status pool you have ever mined on have a look a this post: http://dot-bit.org/forum/viewtopic.php?f=5&t=217&p=1284#p1284 (http://dot-bit.org/forum/viewtopic.php?f=5&t=217&p=1284#p1284)  ;D We need as much people testing and confirming the proper function of different miners as possible.

I am working on creating a bitcoin pool right now but would like to implement this feature, or at least get started testing it.

So there would be just 1 instance of pushpoold running? And 1 instance of namecoind running? Along with a proxy patch of some sort?

How would pushpool tell the mysql databases that it received a valid bitcoin solution or namecoin solution?

As it stands, pushpool simply reports "Y", "Y" for it's "upstream_result" and "our_result" mysql columns. So how would I know that I have mined a namecoin?

Perhaps from the "version" field of the valid solution?

You have a patched bitcoind (and its blockchain), a namecoind (and its blockchain) the merged-mining-proxy that know how to connect to both daemons and the pushpoold that connects to merged-mine-proxy.

 
You don't have to rely on any information from the proxy. You could for example let pushpoold write the shares to the database and monitor the blockchains for generated blocks. Calculate how much valid shares each miner delivers between two blocks for each blockchain. Or you could patch both blockchain  daemons to deliver those information. Both is common amongst current pools

This is already true (and has always been), as anybody can start up their own blockchain. The challenge is still to try to get other people use it (not just mine it). The only difference with merged mining is that any blockchain can now be just as secure as bitcoin, but that doesn't make then as valuable.

It's like we are building this huge proof of work machine, and any future application that wants to use blockchains (and there will be many, not just currencies), can just tap in to existing hashing power. They don't even have to provide much (or at all) financial incentive for miners, as for them there is no downside in adding another blockchain to hash. It only needs to be for something a big part of miners would support for one reason or another, and you get your hashing power.

I see this as strengthening the whole idea of virtual currencies, as it kind of levels the playing field for everyone. Sure, it might eventually devalue BTC (or not), but only if some other virtual currency takes its place because it's thought to be better than BTC for some reason. I see no problem with that.

The downside would be the disk space and bandwidth required to maintain new chains. If what one is able to mine isn't valuable enough to pay for those costs then most people would not support that chain with hashing power.

Why pick an arbitrary block so far in the future to change namecoind? Why not work until development is through then just give a fair amount of notice that clients will need to be upgraded before date x or blocks might get rejected? Better yet just pick a block much closer to actual release date. 24k is a long way off...

Because if you upgrade the clients too soon and not everybody upgrades... then you will risk splitting the blockchain iirc.

And don't forget that NMC will be up to block 18,000 or so within the week I would guess once the difficulty drops to 22k.

Thanks for that.

So what exactly must I do to bitcoind in order to start merged mining on my pool?

Are there any instructions to install this? https://github.com/vinced/namecoin/tree/namecoind-mergedmine (https://github.com/vinced/namecoin/tree/namecoind-mergedmine)

Very interesting project.  I'm not sure if I should be scared or excited.

meeeh... wrong answer . No.hashing.power if incentives <= 0
everyone is free to have it's own block-chain. I would definitely not mine 10% or less of my total hashing power for another block-chain if that percentage it's not equal in price with the main block-chain. Actually I'm free to mine namecoins if I want to support distributed DNS, which I do, but my incentives are low for the moment. Namecoin will have to make it's way like bitcoin did, slowly, gaining it's users trust and no free hash power. It has the same security as bitcoin, don't need to worry bout it being fragile. Just my opinion.

+1 this must be done. I will help test with my Mining Farm server :)

I think this is a very bad idea. (Assuming I understand this correctly)

First, you are polluting the bitcoin blockchain with useless namecoin data and vice versa. So you are increasing the size of the blockchain that everyone has to store for this purpose. This has a non-trivial cost on the whole network.

Second, you are tying the generation of namecoins to the generation of bitcoins. This leads to the value of namecoin being tied to the value of bitcoins. In the end, you are just effectively doubling the number of bitcoins from 21 million to 42 million.

The only benefit is a short term benefit of being able to mine more at the current hashrate. As soon as this is fully implemented, the value of bitcoin/namecoin will just decrease until the total value mined is the same. Because this is a zero sum game. You can't just generate value out of nowhere.

There is a perceived benefit that this will make the namecoin blockchain stronger. That's true, but effectively, because namecoins will be so tied together with bitcoins, it will no longer have its own identity and worth because it will be overruled by the value of bitcoins. Namecoin defines the value of a NMC by domain names. Right now, it costs 50 NMC to get a domain name. If you tie the value of NMC to BTC and BTC has a real value, then it would make the value of domain names either too expensive or too cheap. Let say in the future, 1 BTC is worth $1000 and 1 BTC is pegged at 10 NMC due to this merged mining. This makes 1 NMC worth $100. Is that the right price for a .bit domain name? We don't know. But the value of NMC cannot be changed by market forces because it's pegged to BTC. Assuming bitcoin is still the dominating crypto currency, the usefulness of namecoin's original purpose is gone.

If we go through with this merged mining, we are tying 2 crypto currencies with 2 different goals (finance vs. DNS naming) into 1 fate. This will effectively devalue both currency and likely destroy the usefulness of the auxiliary currency and prevent it from succeeding by itself. And it will add a non-trivial cost to the main currency by dirtying its blockchain.

This may seem like a win-win situation on the surface, but in reality, I believe it's a lose-lose situation for bitcoin and namecoin.

Anybody can still run bitcoind and be none the wiser about namecoin. This will not affect bitcoin's blockchain at all as far as I know.


That is for the market to decide. The current price of NMC to BTC is roughly that of it's generation difficulty now because both currencies are virtually worthless in terms of spending power.

Once namecoins can be (well) used for domain name creation, and bitcoin for buying goods, the market will create it's own prices for both blockchains. I see no reason why difficulty should play a hand in value, it doesn't for bitcoins at least.

Maybe an image helps. :)
Yeah, jumping on bitcoin's back to climb the mountain seems like a win/win solution. But in the end, the destination is different. Bitcoin does a lot more work to climb Mt BTC. Namecoin will eventually realize that he's going up the wrong mountain.

http://img7.imageshack.us/img7/5199/mergedmining.jpg

If miners are working on the same work, wouldn't bitcoin's block also contain namecoin's transactions some how? Otherwise, how could the same share be used for both networks? Someone who understands this better, please correct me.


I think the value and difficulty of a crypto currency is tied closely together. Although I can't prove it, I think it's not just higher value causes higher difficult, but higher difficulty causes higher value also because the blockchain is more secure. Because of that, I don't think both currency can succeed at the same time if their generation/mining/difficulty is tied together.

Saying that the value of NMC is linked to BTC isn't a sane argument as to why this shouldn't be implemented.

The only reason that the difficulty is linked to the exchange rate right now is because I have to choose between mining NMC and BTC.

As an example, let's say the difficulty of NMC is 1/2 the difficulty of BTC right now.
If the exchange rate is more than 2 NMC per BTC, and I want Namecoins, I'd be better off mining BTC and exchanging them to NMC (Thus lowering the exchange rate).
If the exchange rate is less than 2 NMC per BTC, and I want Bitcoins, I'd be better off mining NMC and exchanging them to BTC (Thus increasing the exchange rate).
And so because I can choose between mining NMC and BTC, and I will always do what's the best deal for me, the exchange rate is directly linked to the difficulty.

When I can mine both BTC and NMC at once, the linkedness falls apart completely. Suddenly, if I want BTC, it's best I mine both and exchane the NMC. If I want NMC, it's best I mine both and exchange the BTC.

So now everyone's mining both, so the difficulty becomes equal, and since the miners no longer look at the difficulty and exchange rate of both, and they are no longer linked by difficulty, only by how many people want BTC and how many want NMC.

Since BTC has caught on much more than NMC, I predict the exchange rate for NMC will drop a ton because all the Bitcoin miners will suddenly have Namecoins and want to get Bitcoins (and while the same thing will happen for namecoin miners, there are much fewer of them).

But you would not need to sacrifice your bitcoin hashing to do namecoin (or whatever blockchain) hashing. If you have 1GHash/s of hashing power, with merged mining you could mine bitcoins with 1Ghash and namecoins with 1Ghash. If you refuse to give some project a free ride "just because", even though there is no loss to you, that's your decision, and you are free to do it. I suspect you would be in a minority though.

TeraPool is correct. Merged mining does not pollute the Bitcoin block chain with Namecoin data. The only addition to the chain is a single hash in the coinbase transaction - ie, an additional 33 bytes per block. It isn't significant. This is the whole point of having split chains that share work.

And just to re-iterate.

That "addition to the chain" is only in the namecoin blockchain.

Bitcoiners will be none the wiser unless they switch to a pool that is helping them mine namecoins as well. In which case the bitcoin blockchain is still completely unaffected.

That's wrong. 33 bytes are added to the bitcoin blockchain. As Mike Hearn said, it's not significant. So I agree, it's not really polluting the bitcoin blockchain. But I'm still uneasy about what the consequences to namecoin would be if you tie the generation of namecoin and bitcoin together.

I believe mike was referring to the namecoin blockchain as having to deal with the 33 extra bytes...

There is no way on earth we are going to convince half of the bitcoin nodes to upgrade to help out the namecoin network... if I am wrong on this please correct me but I don't see how I could be.

You don't need to make bitcoin users download a new client. The 33 extra bytes is just the extra nonce stored in the coinbase. Current bitcoin clients will accept new blocks with whatever in the coinbase... they don't care that much. So there's no need to update bitcoin client. But the new namecoin client will check the coinbase in the bitcoin block to validate its blocks. At least that's what I understand.

This merged mining daemon looks very interesting. Are there any tutorials out there on how to get started? Would it be enough to simply compile the source from: https://github.com/vinced/namecoin/tree/namecoind-mergedmine and run that as the namecoin client, run an up to date bitcoin client and point my miners at the merged miner proxy (which in turn would point to the locally running namecoind and bitcoind)?

Wouldn't it be possible to use to parent chain interface to a mining pool such as deepbit or btcguild?

I'm looking forward in seeing how this evolves...

Cheers:)

Yes, coblee is right. The 33 bytes goes into the Bitcoin block chain.

Ermmm.. so do we have to convince the entire bitcoin community to partake in this as well then?

From here: http://dot-bit.org/MergedMining (http://dot-bit.org/MergedMining)

Could someone please explain exactly what the change is? What is in these 33 bytes? Will Namecoin's hashes no longer need to have the required number of starting zeroes, as long the block has some kind of Bitcoin proof-of-work? What exactly is this proof-of-work? How does it relate to these mysterious 33 bytes? How is the different difficulty on the chains dealt with? (Namecoin produces blocks faster than Bitcoin.)
??? ??? ??? ??? ??? ???

You need a new Bitcoin if you want to partake in merged mining. You don't need a new one if you don't care about merged mining - older Bitcoin servers will just ignore the extra 33 bytes.

The 33 bytes are a sha256 hash (32 bytes) and one byte for the length, so, 33. The hash is the root of a merkle tree. As there is only one item in that tree today, it's equivalent to a hash of some data that ties the current namecoin block to the tree root.

You can read the details on the wiki page I posted earlier. It's a complicated technique because Bitcoin wasn't really designed for it, so it must be done in a rather roundabout manner.

Difficulty calculations on NameCoin remain the same as before. The only difference is now there'll likely be more hash power put into the chain because you don't have to choose between namecoin and bitcoin, you can do both. The difficulties are not tied together.

But the economic incentives are such that they soon will be ...

But eventually they will start going in step with each other won't they?

Let's say it's now 80 NC to 1 BC.
Once merged, the amount of hash available to NC would cause a short term spike and many people might hop onto NC mining because of the faster gain. Then difficulty corrects. It would become harder to mine NC, so the exchange would adjust, say to 40NC to 1BC. This would continue until an equilibrium of 1 NC to 1 BC is reached wouldn't it? Or effectively creating 2x the Bitcoin supply as some already mentioned.

Their value wouldn't be equal, but difficulty would. I already posted an argument to this, which everyone seemed to ignore:
https://forum.bitcoin.org/index.php?topic=29074.msg377675#msg377675 (https://forum.bitcoin.org/index.php?topic=29074.msg377675#msg377675)

I read this previously but didn't think it made sense. After a second reading, I think I'm seeing how it might decouple the value of NC to BC but it's still not crystal clear why people won't start equating NC to BC since the cost to produce becomes identical.

If I grew corn in gold plated soil, it would cost millions of dollars to produce an ear of corn. That doesn't mean that anyone's going to spend millions to buy my ear of corn.

Just because 50 NMC took just as much to mine as 50 BTC doesn't mean that anyone's willing to spend 50 BTC on 50 NMC (one domain name) - that's a ridiculous price for one domain name (and nobody uses NMC to buy anything other than domain names at this point). If you have one NMC you're going to have to sell them for a lot less than one BTC, if anyone is going to buy them from you.

Registering a domain costs 12 NMC now, and at the next difficulty it will be 11.2. Get educated, go to school, stay off drugs.

And at block 24000 when this is (hopefully) implemented, it'll be 6.69 NC per domain, which is still too high for the exchange rate to get to 1 btc per nc.

There is no reason to believe that 1 NMC will be equal to 1 BTC due to the perceived value of the two.  However, since both are mined at the same time, there's reason to believe that the exchange rate for both will become mostly fixed to say 10 NMC per 1 BTC, which essentially means the 21m coins cap for BTC has just gone up 10%.  If 1 BTC were considered a dollar, an NMC could be considered a dime.  Add in more currencies and the cap will go up even more, leading to an inflationary currency instead of a deflationary one that many were hoping for.

I'm not sure anyone ever said it would be deflationary except for the scaremongers defending the status quo.

It will most likely be a free market of competing currencies, unless there are draconian authoritarian interventions.

Multi-variate, price:supply:demand.

The developers of NameCoin can do what the want to do.

I am saying that first because you will not hear it when I say what I have to say.

This is not a good idea.  Why?

1. NameCoin's difficulty will increase with out the market deciding if it's a good idea or not.
2. Perception is EVERYTHING and although it's not true that namecoin will cause inflation to bitcoin that's how it will be perceived.

On a personal note I like getting lots of namecoins with me 12 Ghashs I don't want to share with deepbit's 4 THashs!!!
LOL :D

Just my 2 bit cents.


Davinci

BTW  I think the fact that namecoin is only traded with bitcoins helps bitcoins increase in value as there is 1 thing on the market that can only be purchased with bitcoins.

Actually you can trade NMC for USD at Ruxum and IMCEX.

I think everyone here is forgetting that as it currently stands, the average BTC and NMC generation rates are exactly the same. Also, there are exactly three variables that matter: supply, demand, and price. Supply will remain the same (there might be a small adjustment period here), demand isn't affected and it follows that price will stay constant. Difficulty is entirely arbitrary as far as the market is concerned.

I think it'll be good for the stability of the NMC market, and I don't really see a downside to it apart from the fact that for most people it'll probably be better just purchasing NMC instead of mining it themselves as mining on an individual basis will take much longer.

It will increase the cost of an attack, but because the same change will let people attack both networks at the same time, the potential profit are also higher. This means that doing an attack will be just as attractive as it is today.

Are you using all 12 GH/s to mine Namecoins?

Just curious is all. How do you see namecoin in the long run playing out?

Bitcoin will drag it along or it will beat out bitcoin because it's required to buying domain names why bitcoin has no other function except as a currency or the perception as money.


BTW Gold and silver is money and nothing else.

Agreed.

So all that gold and silver Jewelery isn't really gold and silver?

Gold and silver is money and nothing else is money every thing else is credit.

Platinum isn't credit though.

LOL good one. But tell the long dead JP Morgan crook that one he will have a good laugh.

Thanks for trying to explain, but I still don't get it.  Sorry...     What am I missing please? 

A block submitted for solve on the bitcoin network has the hash of the previous block, as well as BTC transactions, and the BTC address of the winning miner, as well as a nonce that was varied endlessly when trying to "solve the block".  To have a valid block you need all these.  Similar for a NMC block.  Right?  Thus, if you are looking for valid BTC blocks, you are looking for BTC blocks which couldn't possibly pass as valid NMC blocks.  I don't see how that could affect NMC in any way either via reward or via helping to secure the network. 

   

I think you are missing the point of this. I read the wiki and I believe this is the idea of this. If it will work or not I am not sure.

His idea if it were to work, would be say you are on a pool that mines on both the bitcoin network and the namecoin network simultaneously


so as your gpu's are hashing and submitting shares
instead of just submitting that share to the bitcoin network
it is also submitting that share to the namecoin network

this is assuming this would work with all bitcoin forks, which I am not sure that it would.

this seems like a really cool idea if someone could make it work.

From a mining perspective there is absolutely no change to the end-user. The pool has to support merged mining, that's it. Then instead of just mining NMC or BTC, you'll be mining both.

The NMC client needs to be updated to accept the new auxiliary chain. The current NMC client doesn't support this functionality, so it will be a forced update. Bitcoin will not be affected in any way.

The talk is that NMC block 19200 is going to be the launch block. Should be about a month away.

Doesn't make a lick of sense to me, sorry.  I mean, I can understand a pool which switches back and forth between mining NMC and BTC or other block chains, based on market value and difficulty, but that is simply switching.  I fail to see how work done in solving one hash or share (effectively a set of lower difficulty solves on ONE block chain) can be applied to another block chain.  Auxilliary chain?  Can you point me to a description please? 

If I submit a batch of low-difficulty solved BTC blocks, which have in them the pool operator as the beneficiary, it is proof of work that I am working for the pool.  This work cannot possibly be accepted by a NMC pool as having any meaning at all in the NMC chain right? 

Ok, if you are talking about interesting pool software to give miner choices or enable intelligent switching, I understand.. however it seems you are discussing a core change to the client.  If you could figure out what I am missing here I would be greatly in your debt.  Thanks :D       

 

https://en.bitcoin.it/wiki/Alternative_Chains
https://github.com/vinced/namecoin/blob/master/doc/README_merged-mining.md

Thanks very much for your help.  I am still a little unclear on the motivation for the "merged mining" proposed change and also surprised that there is not more discussion when an official change to the protocol is being proposed in the near future. 

The wiki seems self contradictory at times; for example it states: 

"One final reason is that Satoshi was opposed to putting non-Bitcoin related data into the main chain. As creator of the system, his opinion should carry a lot of weight with anyone serious about extending it. "

This seems like an argument against such a change for merged mining.   

From section "mining" in githu docs:

"When a miner submits a solution, the solution is submitted to both chains. "

This doesn't make sense.  A solution to BTC chain includes BTC transactions and hashes of previous BTC blocks.  How could this possibly be submitted to a NMC chain or have any relevance as proof of work for the NMC network? 

Finally, what is the motivation here?  I see added complexity and no greater security for either network. 



 

Discussion on the change goes on in the namecoin forums at dot-bit.org if you want to raise questions. The actual developer of the change posts there.

The motivation is that NMC (and other bitcoin-like systems) can all use the same pool of processing power to verify transactions - no need to choose which coin to mine once it is included as an auxiliary chain.


That is why NMC will be an AUXILIARY chain, not part of the main chain.


I don't know know the technical details of the system, so I can't provide a further explanation. The NMC client will need to be updated to be compatible with merged mining.